1.1. Overview of the DOM
Core Interfaces

This section defines a set of objects and interfaces for
accessing and manipulating document objects. The functionality
specified in this section (the Core functionality) is
sufficient to allow software developers and web script authors to
access and manipulate parsed HTML and XML content inside conforming
products. The DOM Core API also allows creation and
population of a Document object using only
DOM API calls. A solution for loading a Document and saving it
persistently is proposed in [DOM Level 3 Load and Save].

1.1.1. The DOM Structure
Model

The DOM presents documents as a hierarchy of Node objects that also
implement other, more specialized interfaces. Some types of nodes
may have child nodes
of various types, and others are leaf nodes that cannot have
anything below them in the document structure. For XML and HTML,
the node types, and which node types they may have as children, are
as follows:

The DOM also specifies a NodeList interface to
handle ordered lists of Nodes, such as the
children of a Node, or the elements returned by the
getElementsByTagName method of the Element interface, and
also a NamedNodeMap interface
to handle unordered sets of nodes referenced by their name
attribute, such as the attributes of an Element. NodeList and NamedNodeMap objects in
the DOM are live; that is, changes to the underlying
document structure are reflected in all relevant NodeList and NamedNodeMap objects.
For example, if a DOM user gets a NodeList object
containing the children of an Element, then
subsequently adds more children to that element (or removes
children, or modifies them), those changes are automatically
reflected in the NodeList, without further
action on the user's part. Likewise, changes to a Node in the tree are
reflected in all references to that Node in NodeList
and NamedNodeMap
objects.

1.1.2. Memory Management

Most of the APIs defined by this specification are
interfaces rather than classes. That means that an
implementation need only expose methods with the defined names and
specified operation, not implement classes that correspond directly
to the interfaces. This allows the DOM APIs to be implemented as a
thin veneer on top of legacy applications with their own data
structures, or on top of newer applications with different class
hierarchies. This also means that ordinary constructors (in the
Java or C++ sense) cannot be used to create DOM objects, since the
underlying objects to be constructed may have little relationship
to the DOM interfaces. The conventional solution to this in
object-oriented design is to define factory methods that
create instances of objects that implement the various interfaces.
Objects implementing some interface "X" are created by a
"createX()" method on the Document interface; this is
because all DOM objects live in the context of a specific
Document.

The Core DOM APIs are designed to be compatible with a wide
range of languages, including both general-user scripting languages
and the more challenging languages used mostly by professional
programmers. Thus, the DOM APIs need to operate across a variety of
memory management philosophies, from language bindings that do not
expose memory management to the user at all, through those (notably
Java) that provide explicit constructors but provide an automatic
garbage collection mechanism to automatically reclaim unused
memory, to those (especially C/C++) that generally require the
programmer to explicitly allocate object memory, track where it is
used, and explicitly free it for re-use. To ensure a consistent API
across these platforms, the DOM does not address memory management
issues at all, but instead leaves these for the implementation.
Neither of the explicit language bindings defined by the DOM API
(for ECMAScript
and Java) require any memory management methods, but DOM bindings
for other languages (especially C or C++) may require such support.
These extensions will be the responsibility of those adapting the
DOM API to a specific language, not the DOM Working Group.

1.1.3. Naming Conventions

While it would be nice to have attribute and method names that
are short, informative, internally consistent, and familiar to
users of similar APIs, the names also should not clash with the
names in legacy APIs supported by DOM implementations. Furthermore,
both OMG IDL and ECMAScript have significant
limitations in their ability to disambiguate names from different
namespaces that make it difficult to avoid naming conflicts with
short, familiar names. So, DOM names tend to be long and
descriptive in order to be unique across all environments.

The Working Group has also attempted to be internally consistent
in its use of various terms, even though these may not be common
distinctions in other APIs. For example, the DOM API uses the
method name "remove" when the method changes the structural model,
and the method name "delete" when the method gets rid of something
inside the structure model. The thing that is deleted is not
returned. The thing that is removed may be returned, when it makes
sense to return it.

1.1.4. Inheritance vs.
Flattened Views of the API

The DOM Core APIs
present two somewhat different sets of interfaces to an XML/HTML
document: one presenting an "object oriented" approach with a
hierarchy of inheritance, and a
"simplified" view that allows all manipulation to be done via the
Node interface
without requiring casts (in Java and other C-like languages) or
query interface calls in COM environments. These
operations are fairly expensive in Java and COM, and the DOM may be
used in performance-critical environments, so we allow significant
functionality using just the Node interface. Because
many other users will find the inheritance hierarchy
easier to understand than the "everything is a Node" approach to
the DOM, we also support the full higher-level interfaces for those
who prefer a more object-oriented API.

In practice, this means that there is a certain amount of
redundancy in the API.
The Working Group considers the "inheritance" approach
the primary view of the API, and the full set of functionality on
Node to be
"extra" functionality that users may employ, but that does not
eliminate the need for methods on other interfaces that an
object-oriented analysis would dictate. (Of course, when the O-O
analysis yields an attribute or method that is identical to one on
the Node interface, we don't
specify a completely redundant one.) Thus, even though there is a
generic nodeName attribute on the Node interface,
there is still a tagName attribute on the Element interface; these
two attributes must contain the same value, but the it is
worthwhile to support both, given the different constituencies the
DOM API must
satisfy.

The UTF-16 encoding was chosen because of its widespread
industry practice. Note that for both HTML and XML, the document
character set (and therefore the notation of numeric character
references) is based on UCS [ISO/IEC 10646]. A single numeric
character reference in a source document may therefore in some
cases correspond to two 16-bit units in a DOMString (a high surrogate
and a low surrogate).

Note: Even though the DOM defines the name of the string
type to be DOMString, bindings may use
different names. For example for Java, DOMString is bound to the
String type because it also uses UTF-16 as its
encoding.

Note: As of August 2000, the OMG IDL specification ([OMG
IDL]) included a wstring type. However, that
definition did not meet the interoperability criteria of the DOM API since it relied on
negotiation to decide the width and encoding of a character.

Note: Even though the DOM uses the type DOMTimeStamp, bindings
may use different types. For example for Java, DOMTimeStamp is
bound to the long type. In ECMAScript, DOMTimeStamp is bound to
the Date type because the range of the
integer type is too small.

Note: Even though the DOM uses the type DOMUserData, bindings may
use different types. For example, in Java DOMUserData is bound to
the Object type, while in ECMAScript DOMUserData is bound
to any type.

Note: Even though the DOM uses the type DOMObject, bindings may use
different types. For example, in Java and ECMAScript DOMObject is
bound to the Object type.

1.1.9. String comparisons in
the DOM

The DOM has many interfaces that imply string matching. HTML
processors generally assume an uppercase (less often, lowercase)
normalization of names for such things as elements, while XML is
explicitly case sensitive. For the purposes of the DOM, string
matching is performed purely by binary comparison of the 16-bit units of
the DOMString. In
addition, the DOM assumes that any case normalizations take place
in the processor, before the DOM structures are built.

The W3C Text normalization, as defined in [CharModel],
is assumed to happen at serialization time. The DOM Level 3 Load
and Save module [DOM Level 3 Load and Save] provides a
serialization mechanism (see the DOMWriter interface,
section 2.3.1) and defines the
"ls-normalize-characters" to assure that text is
serialized in the W3C Text Normalization form. Other serialization
mechanisms built on top of the DOM Level 3 Core also have to assure
that text is serialized in the W3C Text Normalization form.

(ED: We need to review the
case sensitivity of methods and attributes and how it fits with XML
and HTML. Current wording is not clear at all ... )

1.1.10. XML
Namespaces

The DOM Level 2 (and higher) supports XML namespaces [XML
Namespaces] by augmenting several interfaces of the DOM Level 1
Core to allow creating and manipulating elements and attributes
associated to a namespace.

As far as the DOM is concerned, special attributes used for
declaring XML
namespaces are still exposed and can be manipulated just
like any other attribute. However, nodes are permanently bound to
namespace URIs
as they get created. Consequently, moving a node within a document,
using the DOM, in no case results in a change of its namespace prefix or
namespace URI. Similarly, creating a node with a namespace prefix
and namespace URI, or changing the namespace prefix of a node, does
not result in any addition, removal, or modification of any special
attributes for declaring the appropriate XML namespaces. Namespace
validation is not enforced; the DOM application is responsible. In
particular, since the mapping between prefixes and namespace URIs
is not enforced, in general, the resulting document cannot be
serialized naively. For example, applications may have to declare
every namespace in use when serializing a document.

In general, the DOM implementation (and higher) doesn't perform
any URI normalization or canonicalization. The URIs given to the
DOM are assumed to be valid (e.g., characters such as white spaces
are properly escaped), and no lexical checking is performed.
Absolute URI references are treated as strings and compared literally.
How relative namespace URI references are treated is undefined. To
ensure interoperability only absolute namespace URI references
(i.e., URI references beginning with a scheme name and a colon)
should be used. Applications should use the value null as the
namespaceURI parameter for methods if they wish to have no
namespace. In programming languages where empty strings can be
differentiated from null, the way empty strings are treated, when
given as a namespace URI to a DOM Level 2 method, is implementation
dependent. This is true even though the DOM does no lexical
checking of URIs.

Note: In the DOM, all namespace declaration attributes
are by definition bound to the namespace URI: "http://www.w3.org/2000/xmlns/".
These are the attributes whose namespace prefix or
qualified
name is "xmlns". Although, at the time of writing, this is
not part of the XML Namespaces specification [XML
Namespaces], it is planned to be incorporated in a future
revision.

In a document with no namespaces, the child list of an EntityReference node is
always the same as that of the corresponding Entity. This is not true
in a document where an entity contains unbound namespace prefixes.
In such a case, the descendants of the
corresponding EntityReference nodes may
be bound to different namespace URIs,
depending on where the entity references are. Also, because, in the
DOM, nodes always remain bound to the same namespace URI, moving
such EntityReference nodes can
lead to documents that cannot be serialized. This is also true when
the DOM Level 1 method createEntityReference of the Document interface is
used to create entity references that correspond to such entities,
since the descendants of the
returned EntityReference are
unbound. The DOM Level 2 does not support any mechanism to resolve
namespace prefixes. For all of these reasons, use of such entities
and entity references should be avoided or used with extreme care.
A future Level of the DOM may include some additional support for
handling these.

The new methods, such as createElementNS and
createAttributeNS of the Document interface, are
meant to be used by namespace aware applications. Simple
applications that do not use namespaces can use the DOM Level 1
methods, such as createElement and
createAttribute. Elements and attributes created in
this way do not have any namespace prefix, namespace URI, or local
name.

Note: Given that the property [in-scope namespaces]
defined in [XML Information set] is not
accessible from DOM Level 3 Core, the properties [prefix] and
[namespace name] defined by the Namespace Information Item in [XML
Information set] are not accessible from DOM Level 3 Core.
However, [DOM Level 3 XPath] does provide a
way to access them.

Note: DOM Level 1 methods are namespace ignorant.
Therefore, while it is safe to use these methods when not dealing
with namespaces, using them and the new ones at the same time
should be avoided. DOM Level 1 methods solely identify attribute
nodes by their nodeName. On the contrary, the DOM
Level 2 methods related to namespaces, identify attribute nodes by
their namespaceURI and localName. Because
of this fundamental difference, mixing both sets of methods can
lead to unpredictable results. In particular, using
setAttributeNS, an element may have two
attributes (or more) that have the same nodeName, but
different namespaceURIs. Calling
getAttribute with that nodeName could
then return any of those attributes. The result depends on the
implementation. Similarly, using setAttributeNode, one
can set two attributes (or more) that have different
nodeNames but the same prefix and
namespaceURI. In this case
getAttributeNodeNS will return either attribute, in an
implementation dependent manner. The only guarantee in such cases
is that all methods that access a named item by its
nodeName will access the same item, and all methods
which access a node by its URI and local name will access the same
node. For instance, setAttribute and
setAttributeNS affect the node that
getAttribute and getAttributeNS,
respectively, return.

1.1.11. Base
URIs

The DOM Level 3 adds support for the [base URI] property defined
in [XML
Information set] by providing a new attribute on the Node interface that
exposes this information. However, unlike the
namespaceURI attribute, the baseURI
attribute is not a static piece of information that every node
carries. Instead, it is a value that is dynamically computed
according to [XML Base]. This means its value
depends on the location of the node in the tree and moving the node
from one place to another in the tree may affect its value. Other
changes, such as adding or changing an xml:base attribute on the
node being queried or one of its ancestors may also affect its
value.

One consequence of this it that when external entity references
are expanded while building a Document one may need to
add, or update it if one already exists, an xml:base attribute to
the Element nodes
originally contained in the entity being expanded so that the
baseURI returns the correct value. In the case of ProcessingInstruction
nodes originally contained in the entity being expanded the
information is lost. [DOM Level 3 Load and Save] handles
elements as described here and generates a warning in the latter
case.

This does not work for PIs.Resolution: Info is lost, a warning is generated (Telcon 29
Apr 2002)

1.1.12. Mixed DOM
implementations

As new XML vocabularies are developed, those defining the
vocabularies are also beginning to define specialized APIs for
manipulating XML instances of those vocabularies. This is usually
done by extending the DOM to provide interfaces and methods that
perform operations frequently needed their users. For example, the
MathML [MathML 2.0] and SVG [SVG 1.0]
specifications are developing DOM extensions to allow users to
manipulate instances of these vocabularies using semantics
appropriate to images and mathematics (respectively) as well as the
generic DOM XML semantics. Instances of SVG or MathML are often
embedded in XML documents conforming to a different schema such as
XHTML.

While the XML Namespaces Recommendation provides a mechanism for
integrating these documents at the syntax level, it has become
clear that the DOM Level 2 Recommendation [DOM Level 2
Core] is not rich enough to cover all the issues that have been
encountered in having these different DOM implementations be used
together in a single application. DOM Level 3 deals with the
requirements brought about by embedding fragments written according
to a specific markup language (the embedded component) in a
document where the rest of the markup is not written according to
that specific markup language (the host document). It does not deal
with fragments embedded by reference or linking.

A DOM implementation supporting DOM Level 3 Core should be able
to collaborate with subcomponents implementing specific DOMs to
assemble a compound document that can be traversed and manipulated
via DOM interfaces as if it were a seamless whole.

The normal typecast operation on an object should support the
interfaces expected by legacy code for a given document type.
Typecasting techniques may not be adequate for selecting between
multiple DOM specializations of an object which were combined at
run time, because they may not all be part of the same object as
defined by the binding's object model. Conflicts are most obvious
with the Document
object, since it is shared as owner by the rest of the document. In
a homogeneous document, elements rely on the Document for
specialized services and construction of specialized nodes. In a
heterogeneous document, elements from different modules expect
different services and APIs from the same Document object, since
there can only be one owner and root of the document hierarchy.

1.1.13. Bootstrapping

Because previous versions of the DOM specification only defined
a set of interfaces, applications had to rely on some
implementation dependent code to start from. However, hard-coding
the application to a specific implementation prevents the
application from running on other implementations and from using
the most-suitable implementation of the environment. At the same
time, implementations may also need to load modules or perform
other setup to efficiently adapt to different and sometimes
mutually-exclusive feature sets.

To solve these problems this specification introduces a
DOMImplementationRegistry object with a function that
lets an application find implementations, based on the specific
features it requires. How this object is found and what it exactly
looks like is not defined here, because this cannot be done in a
language-independent manner. Instead, each language binding defines
its own way of doing this. See Java Language Binding and ECMAScript Language
Binding for specifics.

In all cases, though, the DOMImplementationRegistry
provides a getDOMImplementation method accepting a
features string, which is passed to every known DOMImplementationSource
until a suitable DOMImplementation is
found and returned. The DOMImplementationRegistry also
provides a getDOMImplementations method accepting a
features string, which is passed to every known DOMImplementationSource,
and returns a list of suitable DOMImplementations. Those
two methods are the same as the ones found on the DOMImplementationSource
interface defined below.

Should the method getDOMImplementation be called
byFeature instead?Resolution: No. (F2F 31 Jul 2001)

1.2. Fundamental
Interfaces

The interfaces within this section are considered
fundamental, and must be fully implemented by all
conforming implementations of the DOM, including all HTML DOM
implementations [DOM Level 2 HTML], unless otherwise
specified.

A DOM application may use the hasFeature(feature,
version) method of the DOMImplementation
interface with parameter values "Core" and "3.0" (respectively) to
determine whether or not this module is supported by the
implementation. Any implementation that conforms to DOM Level 3 or
a DOM Level 3 module must conform to the Core module. Please refer
to additional information about conformance in this specification. The DOM Level 3
Core module is backward compatible with the DOM Level 2 Core [DOM Level
2 Core] module, i.e. a DOM Level 3 Core implementation who
returns true for "Core" with the version
number "3.0" must also return true for
this feature when the version number is
"2.0", "" or, null.

DOM operations only raise exceptions in "exceptional"
circumstances, i.e., when an operation is impossible to perform
(either for logical reasons, because data is lost, or because the
implementation has become unstable). In general, DOM methods return
specific error values in ordinary processing situations, such as
out-of-bound errors when using NodeList.

Implementations should raise other exceptions under other
circumstances. For example, implementations should raise an
implementation-dependent exception if a null argument
is passed when null was not expected.

Some languages and object systems do not support the concept of
exceptions. For such systems, error conditions may be indicated
using native error reporting mechanisms. For some bindings, for
example, methods may return error codes similar to those listed in
the corresponding method descriptions.

If an invalid or illegal character is specified, such as in a
name. See production
2 in the XML specification for the definition of a legal
character, and production
5 for the definition of a legal name character.

If a call to a method such as insertBefore or
removeChild would make the Node invalid with
respect to "partial
validity", this exception would be raised and the
operation would not be done. This code is used in [DOM Level 3
Validation]. Refer to this specification for further
information.

The DOMStringList interface provides the
abstraction of an ordered collection of parallel pairs of name and
namespace values, without defining or constraining how this
collection is implemented. The items in the
DOMStringList are accessible via an integral index,
starting from 0.

The NameList interface provides the abstraction of
an ordered collection of parallel pairs of name and namespace
values, without defining or constraining how this collection is
implemented. The items in the NameList are accessible
via an integral index, starting from 0.

The DOMImplementationList interface provides the
abstraction of an ordered collection of DOM implementations,
without defining or constraining how this collection is
implemented. The items in the DOMImplementationList
are accessible via an integral index, starting from 0.

This interface permits a DOM implementer to supply one or more
implementations, based upon requested features. Each implemented
DOMImplementationSource object is listed in the
binding-specific list of available sources so that its DOMImplementation objects
are made available.

A string that specifies which features are required. This is a
space separated list in which each feature is specified by its name
optionally followed by a space and a version number. This is
something like: "XML 1.0 Traversal Events 2.0"

A string that specifies which features are required. This is a
space separated list in which each feature is specified by its name
optionally followed by a space and a version number. This is
something like: "XML 1.0 Traversal Events 2.0"

Creates a DOM Document object of the specified
type with its document element.
Note that based on the DocumentType given to
create the document, the implementation may instantiate specialized
Document objects
that support additional features than the "Core", such as "HTML"
[DOM
Level 2 HTML]. On the other hand, setting the DocumentType after
the document was created makes this very unlikely to happen.
Alternatively, specialized Document creation methods,
such as createHTMLDocument [DOM Level 2
HTML], can be used to obtain specific types of Document
objects.

INVALID_CHARACTER_ERR: Raised if the specified qualified name
contains an illegal character.

NAMESPACE_ERR: Raised if the qualifiedName is
malformed, if the qualifiedName has a prefix and the
namespaceURI is null, or if the
qualifiedName is null and the
namespaceURI is different from null, or
if the qualifiedName has a prefix that is "xml" and
the namespaceURI is different from "http://www.w3.org/XML/1998/namespace"
[XML
Namespaces], or if the DOM implementation does not support the
"XML" feature but a non-null namespace URI was
provided, since namespaces were defined by XML.

WRONG_DOCUMENT_ERR: Raised if doctype has already
been used with a different document or was created from a different
implementation.

NOT_SUPPORTED_ERR: May be raised if the implementation does not
support the feature "XML" and the language exposed through the
Document does not support XML Namespaces (such as [HTML
4.01]).

This method returns a specialized object which
implements the specialized APIs of the specified feature and
version. The specialized object may also be obtained by using
binding-specific casting methods but is not necessarily expected
to, as discussed in Mixed DOM
implementations. This method also allow the implementation to
provide specialized objects which do not support the
DOMImplementation interface.

This is the version number of the feature to test. If the
version is null or the empty string, supporting any
version of the feature will cause the method to return an object
that supports at least one version of the feature.

Returns an object which implements the specialized APIs of the
specified feature and version, if any, or null if
there is no object which implements interfaces associated with that
feature. If the DOMObject returned by this
method implements the DOMImplementation interface, it
must delegate to the primary core Node and not return
results inconsistent with the primary core Node such as attributes,
childNodes, etc.

The name of the feature to test (case-insensitive). The values
used by DOM features are defined throughout the DOM Level 3
specifications and listed in the Conformance section. The
name must be an XML
name. To avoid possible conflicts, as a convention, names
referring to features defined outside the DOM specification should
be made unique.

This is the version number of the feature to test. In Level 3,
the string can be either "3.0", "2.0" or "1.0". If the version is
null or empty string, supporting any version of the
feature causes the method to return true.

Return Value

boolean

true if the feature is implemented in the specified
version, false otherwise.

DocumentFragment is a "lightweight" or "minimal" Document object. It is
very common to want to be able to extract a portion of a document's
tree or to create a new fragment of a document. Imagine
implementing a user command like cut or rearranging a document by
moving fragments around. It is desirable to have an object which
can hold such fragments and it is quite natural to use a Node for
this purpose. While it is true that a Document object could
fulfill this role, a Document object can
potentially be a heavyweight object, depending on the underlying
implementation. What is really needed for this is a very
lightweight object. DocumentFragment is such an
object.

Furthermore, various operations -- such as inserting nodes as
children of another Node -- may take
DocumentFragment objects as arguments; this results in
all the child nodes of the DocumentFragment being
moved to the child list of this node.

The children of a DocumentFragment node are zero or
more nodes representing the tops of any sub-trees defining the
structure of the document. DocumentFragment nodes do
not need to be well-formed XML
documents (although they do need to follow the rules
imposed upon well-formed XML parsed entities, which can have
multiple top nodes). For example, a DocumentFragment
might have only one child and that child node could be a Text node. Such a
structure model represents neither an HTML document nor a
well-formed XML document.

When a DocumentFragment is inserted into a Document (or indeed any
other Node that
may take children) the children of the
DocumentFragment and not the
DocumentFragment itself are inserted into the Node. This makes the
DocumentFragment very useful when the user wishes to
create nodes that are siblings; the
DocumentFragment acts as the parent of these nodes so
that the user can use the standard methods from the Node
interface, such as insertBefore and
appendChild.

Note: The properties [notations] and [unparsed entities]
defined by the Document Information Item in [XML Information
set] are accessible through the DocumentType interface.
The property [all declarations processed] is not accessible through
the DOM API.

The Document interface represents the entire HTML
or XML document. Conceptually, it is the root of the document
tree, and provides the primary access to the document's data.

Since elements, text nodes, comments, processing instructions,
etc. cannot exist outside the context of a Document,
the Document interface also contains the factory
methods needed to create these objects. The Node objects created
have a ownerDocument attribute which associates them
with the Document within whose context they were
created.

The Document Type Declaration (see DocumentType) associated
with this document. For HTML documents as well as XML documents
without a document type declaration this returns
null.
This provides direct access to the DocumentType node, child
node of this Document. This node can be set at
document creation time and later changed through the use of child
nodes manipulation methods, such as insertBefore, or
replaceChild. Note, however, that while some
implementations may instantiate different types of
Document objects supporting additional features than
the "Core", such as "HTML" [DOM Level 2 HTML], based on the DocumentType specified at
creation time, changing it afterwards is very unlikely to result in
a change of the features supported.

The location of the document or null if
undefined.
Beware that when the Document supports the feature
"HTML" [DOM Level 2 HTML], the href
attribute of the HTML BASE element takes precedence over this
attribute.

An attribute specifying whether error checking is enforced or
not. When set to false, the implementation is free to
not test every possible error case normally defined on DOM
operations, and not raise any DOMException. In case of
error, the behavior is undefined. This attribute is
true by default.

An attribute specifying, as part of the XML declaration, the
version number of this document. This is null when
unspecified.This attribute
represents the property [version] defined in [XML Information
set].

Changes the ownerDocument of a
node, its children, as well as the attached attribute nodes if
there are any. If the node has a parent it is first removed from
its parent child list. This effectively allows moving a subtree
from one document to another. The following list describes the
specifics for each type of node.

ATTRIBUTE_NODE

The ownerElement attribute is set to
null and the specified flag is set to
true on the adopted Attr. The descendants of
the source Attr are recursively
adopted.

Specified attribute nodes of the source element are
adopted, and the generated Attr nodes. Default
attributes are discarded, though if the document being adopted into
defines default attributes for this element name, those are
assigned. The descendants of the source element are recursively
adopted.

Only the EntityReference node
itself is adopted, the descendants are discarded, since the source
and destination documents might have defined the entity
differently. If the document being imported into provides a
definition for this entity name, its value is assigned.

Should this method simply return null when it fails? How
"exceptional" is failure for this method?Resolution: Stick with raising exceptions only in
exceptional circumstances, return null on failure (F2F 19 Jun
2000).

Does this affect keys and hashCode's of the adopted subtree
nodes?
If so, what about readonly-ness of key and hashCode?
if not, would appendChild affect keys/hashCodes or would it
generate exceptions if key's are duplicate?Resolution: Both keys and hashcodes have been dropped.

Creates an Attr of the given name.
Note that the Attr instance can then be
set on an Element
using the setAttributeNode method.
To create an attribute with a qualified name and namespace URI,
use the createAttributeNS method.

Creates an element of the type specified. Note
that the instance returned implements the Element interface, so
attributes can be specified directly on the returned object.
In addition, if there are known attributes with default values, Attr nodes
representing them are automatically created and attached to the
element.
To create an element with a qualified name and namespace URI,
use the createElementNS method.

The name of the element type to instantiate. For XML, this is
case-sensitive, otherwise it depends on the case-sentivity of the
markup language in use. In that case, the name is mapped to the
canonical form of that markup by the DOM implementation.

Creates an EntityReference object. In
addition, if the referenced entity is known, the child list of the
EntityReference node is
made the same as that of the corresponding Entity node.

Note: If any descendant of the Entity node has an unbound
namespace
prefix, the corresponding descendant of the created EntityReference node
is also unbound; (its namespaceURI is
null). The DOM Level 2 and 3 do not support any
mechanism to resolve namespace prefixes in this case.

Returns the Element that has an ID
attribute with the given value. If no such element exists, this
returns null. If more than one element has an ID
attribute with that value, what is returned is undefined.
The DOM implementation needs to have information that says which
attributes are of type ID. This information can come from
validating the document against a grammar or from the use of the
setIdAttribute method and its siblings on Element. To query whether
an attribute is of type ID see isId on Attr.

Note: Attributes with the name "ID" or "id" are not of
type ID unless so defined.

Imports a node from another document to this
document. The returned node has no parent; (parentNode
is null). The source node is not altered or removed
from the original document; this method creates a new copy of the
source node.
For all nodes, importing a node creates a node object owned by the
importing document, with attribute values identical to the source
node's nodeName and nodeType, plus the
attributes related to namespaces (prefix,
localName, and namespaceURI). As in the
cloneNode operation, the source node is not altered.
User data associated to the imported node is not carried over.
However, if any UserDataHandlers has
been specified along with the associated data these handlers will
be called with the appropriate parameters before this method
returns.
Additional information is copied as appropriate to the
nodeType, attempting to mirror the behavior expected
if a fragment of XML or HTML source was copied from one document to
another, recognizing that the two documents may have different DTDs
in the XML case. The following list describes the specifics for
each type of node.

ATTRIBUTE_NODE

The ownerElement attribute is set to
null and the specified flag is set to
true on the generated Attr. The descendants of the
source Attr are recursively
imported and the resulting nodes reassembled to form the
corresponding subtree.
Note that the deep parameter has no effect on Attr nodes; they always
carry their children with them when imported.

Specified attribute nodes of the source element are
imported, and the generated Attr nodes are attached
to the generated Element. Default
attributes are not copied, though if the document being
imported into defines default attributes for this element name,
those are assigned. If the importNodedeep parameter was set to true, the descendants of the
source element are recursively imported and the resulting nodes
reassembled to form the corresponding subtree.

ENTITY_NODE

Entity nodes
can be imported, however in the current release of the DOM the DocumentType is
readonly. Ability to add these imported nodes to a DocumentType will be
considered for addition to a future release of the DOM.
On import, the publicId, systemId, and
notationName attributes are copied. If a
deep import is requested, the descendants of the the
source Entity are
recursively imported and the resulting nodes reassembled to form
the corresponding subtree.

ENTITY_REFERENCE_NODE

Only the EntityReference itself is
copied, even if a deep import is requested, since the
source and destination documents might have defined the entity
differently. If the document being imported into provides a
definition for this entity name, its value is assigned.

NOTATION_NODE

Notation nodes
can be imported, however in the current release of the DOM the DocumentType is
readonly. Ability to add these imported nodes to a DocumentType will be
considered for addition to a future release of the DOM.
On import, the publicId and systemId
attributes are copied.
Note that the deep parameter has no effect on this
type of nodes since they cannot have any children.

PROCESSING_INSTRUCTION_NODE

The imported node copies its target and
data values from those of the source node.
Note that the deep parameter has no effect on this
type of nodes since they cannot have any children.

TEXT_NODE, CDATA_SECTION_NODE, COMMENT_NODE

These three types of nodes inheriting from CharacterData copy their
data and length attributes from those of
the source node.
Note that the deep parameter has no effect on these
types of nodes since they cannot have any children.

If true, recursively import the subtree under the
specified node; if false, import only the node itself,
as explained above. This has no effect on nodes that cannot have
any children, and on Attr, and EntityReference
nodes.

This method acts as if the document was going
through a save and load cycle, putting the document in a "normal"
form. The actual result depends on the features being set and
governing what operations actually take place. See DOMConfiguration for
details.
Noticeably this method normalizes Text nodes, makes the
document "namespace wellformed", according to the algorithm
described in Namespace
normalization, by adding missing namespace declaration
attributes and adding or changing namespace prefixes, updates the
replacement tree of EntityReference nodes,
normalizes attribute values, etc.
Mutation events, when supported, are generated to reflect the
changes occuring on the document.
See Namespace
normalization for details on how namespace declaration
attributes and prefixes are normalized.

Should this really be on Node?Resolution: Yes, but this only works on Document, Element,
and DocumentFragment. On other types it is a no-op. (F2F 1 Aug
2000).
No. Now that it does much more than simply fixing namespaces it
only makes sense on Document (F2F 26 Sep 2001).

Rename an existing node of type
ELEMENT_NODE or ATTRIBUTE_NODE.
When possible this simply changes the name of the given node,
otherwise this creates a new node with the specified name and
replaces the existing node with the new node as described
below.
If simply changing the name of the given node is not possible, the
following operations are performed: a new node is created, any
registered event listener is registered on the new node, any user
data attached to the old node is removed from that node, the old
node is removed from its parent if it has one, the children are
moved to the new node, if the renamed node is an Element its attributes
are moved to the new node, the new node is inserted at the position
the old node used to have in its parent's child nodes list if it
has one, the user data that was attached to the old node is
attached to the new node.
When the node being renamed is an Element only the
specified attributes are moved, default attributes originated from
the DTD are updated according to the new element name. In addition,
the implementation may update default attributes from other
schemas. Applications should use normalizeDocument() to guarantee
these attributes are up-to-date.
When the node being renamed is an Attr that is attached to
an Element, the
node is first removed from the Element attributes map.
Then, once renamed, either by modifying the existing node or
creating a new one as described above, it is put back.
In addition,

a user data event NODE_RENAMED is fired,

when the implementation supports the feature "MutationEvents",
each mutation operation involved in this method fires the
appropriate event, and in the end the event
DOMElementNameChanged or
DOMAttributeNameChanged is fired.

The Node interface is the primary datatype for the
entire Document Object Model. It represents a single node in the
document tree. While all objects implementing the Node
interface expose methods for dealing with children, not all objects
implementing the Node interface may have children. For
example, Text
nodes may not have children, and adding children to such nodes
results in a DOMException being
raised.

The attributes nodeName, nodeValue and
attributes are included as a mechanism to get at node
information without casting down to the specific derived interface.
In cases where there is no obvious mapping of these attributes for
a specific nodeType (e.g., nodeValue for
an Element or
attributes for a Comment), this returns
null. Note that the specialized interfaces may contain
additional and more convenient mechanisms to get and set the
relevant information.

A bitmask indicating the relative document position of a node
with respect to another node.

If the two nodes being compared are the same node, then no flags
are set on the return.

Otherwise, the order of two nodes is determined by looking for
common containers -- containers which contain both. A node directly
contains any child nodes. A node also directly contains any other
nodes attached to it such as attributes contained in an element or
entities and notations contained in a document type. Nodes
contained in contained nodes are also contained, but less-directly
as the number of intervening containers increases.

If there is no common container node, then the order is based
upon order between the root container of each node that is in no
container. In this case, the result is disconnected and
implementation-specific. This result is stable as long as these
outer-most containing nodes remain in memory and are not inserted
into some other containing node. This would be the case when the
nodes belong to different documents or fragments, and cloning the
document or inserting a fragment might change the order.

If one of the nodes being compared contains the other node, then
the container precedes the contained node, and reversely the
contained node follows the container. For example, when comparing
an element against its own attribute or child, the element node
precedes its attribute node and its child node, which both follow
it.

If neither of the previous cases apply, then there exists a
most-direct container common to both nodes being compared. In this
case, the order is determined based upon the two determining nodes
directly contained in this most-direct common container that either
are or contain the corresponding nodes being compared.

If these two determining nodes are both child nodes, then the
natural DOM order of these determining nodes within the containing
node is returned as the order of the corresponding nodes. This
would be the case, for example, when comparing two child elements
of the same element.

If one of the two determining nodes is a child node and the
other is not, then the corresponding node of the child node follows
the corresponding node of the non-child node. This would be the
case, for example, when comparing an attribute of an element with a
child element of the same element.

If neither of the two determining node is a child node and one
determining node has a greater value of nodeType than
the other, then the corresponding node precedes the other. This
would be the case, for example, when comparing an entity of a
document type against a notation of the same document type.

If neither of the two determining node is a child node and
nodeType is the same for both determining nodes, then
an implementation-dependent order between the determining nodes is
returned. This order is stable as long as no nodes of the same
nodeType are inserted into or removed from the direct container.
This would be the case, for example, when comparing two attributes
of the same element, and inserting or removing additional
attributes might change the order between existing attributes.

A NamedNodeMap containing
the attributes of this node (if it is an Element) or
null otherwise.If no
namespace declaration appear in the attributes, this attribute
represents the property [attributes] defined in [XML Information
set]. If namespace declarations appear
in the attributes, this attribute combines the properties
[attributes] and [namespace attributes] defined in [XML Information
set].

The absolute base URI of this node or null if
undefined. This value is computed according to [XML Base].
However, when the Document supports the
feature "HTML" [DOM Level 2 HTML], the base URI is
computed using first the value of the href attribute of the HTML
BASE element if any, and the value of the documentURI
attribute from the Document interface
otherwise.When the node
is an Element, a
Document or a a ProcessingInstruction,
this attribute represents the properties [base URI] defined in [XML
Information set]. When the node is a Notation, an Entity, or an EntityReference
representing an unexpanded entity reference or an internal entity
reference, this attribute represents the properties [declaration
base URI] in the [XML Information set] . When the node
is an EntityReference representing an external entity reference
this is the absolute URI of the entity.

Should this only be on Document, Element,
ProcessingInstruction, Entity, and Notation nodes, according to the
infoset? If not, what is it equal to on other nodes? Null? An empty
string? I think it should be the parent's.Resolution: No.

Returns the local part of the qualified name of
this node.When the
node is Element,
or Attr, this
attribute represents the properties [local name] defined in [XML
Information set].
For nodes of any type other than ELEMENT_NODE and
ATTRIBUTE_NODE and nodes created with a DOM Level 1
method, such as createElement from the Document interface, this is
always null.

The namespace
URI of this node, or null if it is
unspecified.When the node is Element, or Attr, this attribute
represents the properties [namespace name] defined in [XML Information
set].
This is not a computed value that is the result of a namespace
lookup based on an examination of the namespace declarations in
scope. It is merely the namespace URI given at creation time.
For nodes of any type other than ELEMENT_NODE and
ATTRIBUTE_NODE and nodes created with a DOM Level 1
method, such as createElement from the Document interface, this is
always null.

Note: Per the Namespaces in XML Specification
[XML
Namespaces] an attribute does not inherit its namespace from
the element it is attached to. If an attribute is not explicitly
given a namespace, it simply has no namespace.

The namespace
prefix of this node, or null if it is
unspecified.When the node is
Element, or Attr, this attribute
represents the properties [prefix] defined in [XML Information
set].
Note that setting this attribute, when permitted, changes the
nodeName attribute, which holds the qualified name, as
well as the tagName and name attributes
of the Element
and Attr
interfaces, when applicable.
Setting the prefix to null makes it unspecified,
setting it to an empty string is implementation dependent.
Note also that changing the prefix of an attribute that is known to
have a default value, does not make a new attribute with the
default value and the original prefix appear, since the
namespaceURI and localName do not
change.
For nodes of any type other than ELEMENT_NODE and
ATTRIBUTE_NODE and nodes created with a DOM Level 1
method, such as createElement from the Document interface, this is
always null.

INVALID_CHARACTER_ERR: Raised if the specified prefix contains
an illegal character.

NO_MODIFICATION_ALLOWED_ERR: Raised if this node is
readonly.

NAMESPACE_ERR: Raised if the specified prefix is
malformed per the Namespaces in XML specification, if the
namespaceURI of this node is null, if the
specified prefix is "xml" and the namespaceURI of this
node is different from "http://www.w3.org/XML/1998/namespace",
if this node is an attribute and the specified prefix is "xmlns"
and the namespaceURI of this node is different from
"http://www.w3.org/2000/xmlns/",
or if this node is an attribute and the qualifiedName
of this node is "xmlns" [XML Namespaces].

This attribute returns the text content of this node and its
descendants. When it is defined to be null, setting it has no
effect. When set, any possible children this node may have are
removed and replaced by a single Text node containing the
string this attribute is set to. On getting, no serialization is
performed, the returned string does not contain any markup. No
whitespace normalization is performed, the returned string does not
contain the element content whitespaces Fundamental
Interfaces. Similarly, on setting, no parsing is performed
either, the input string is taken as pure textual content.
The string returned is made of the text content of this node
depending on its type, as defined below:

Should any whitespace normalization be performed? MS' text
property doesn't but what about "ignorable whitespace"?Resolution: Does not perform any whitespace normalization
and ignores "ignorable whitespace".

Setting the text property on a Document, Document Type, or
Notation node is an error for MS. How do we expose it? Exception?
Which one?Resolution: (teleconference 23 May 2001) consistency with
nodeValue. Remove Document from the list.

Returns a duplicate of this node, i.e., serves
as a generic copy constructor for nodes. The duplicate node has no
parent; (parentNode is null.) and no user
data. User data associated to the imported node is not carried
over. However, if any UserDataHandlers has
been specified along with the associated data these handlers will
be called with the appropriate parameters before this method
returns.
Cloning an Element copies all
attributes and their values, including those generated by the XML
processor to represent defaulted attributes, but this method does
not copy any children it contains unless it is a deep clone. This
includes text contained in an the Element since the text is
contained in a child Text node. Cloning an
Attribute directly, as opposed to be cloned as part of
an Element cloning
operation, returns a specified attribute (specified is
true). Cloning an Attribute always clones
its children, since they represent its value, no matter whether
this is a deep clone or not. Cloning an EntityReference
automatically constructs its subtree if a corresponding Entity is available, no
matter whether this is a deep clone or not. Cloning any other type
of node simply returns a copy of this node.
Note that cloning an immutable subtree results in a mutable copy,
but the children of an EntityReference clone are
readonly. In
addition, clones of unspecified Attr nodes are specified.
And, cloning Document, DocumentType, Entity, and Notation nodes is
implementation dependent.

Parameters

deep of type
boolean

If true, recursively clone the subtree under the
specified node; if false, clone only the node itself
(and its attributes, if it is an Element).

This method returns a specialized object which
implements the specialized APIs of the specified feature and
version. The specialized object may also be obtained by using
binding-specific casting methods but is not necessarily expected
to, as discussed in Mixed DOM
implementations. This method also allow the implementation to
provide specialized objects which do not support the
Node interface.

This is the version number of the feature to test. If the
version is null or the empty string, supporting any
version of the feature will cause the method to return an object
that supports at least one version of the feature.

Returns an object which implements the specialized APIs of the
specified feature and version, if any, or null if
there is no object which implements interfaces associated with that
feature. If the DOMObject returned by this
method implements the Node interface, it must delegate
to the primary core Node and not return results
inconsistent with the primary core Node such as
attributes, childNodes, etc.

Inserts the node newChild before
the existing child node refChild. If
refChild is null, insert
newChild at the end of the list of children.
If newChild is a DocumentFragment object,
all of its children are inserted, in the same order, before
refChild. If the newChild is already in
the tree, it is first removed.

HIERARCHY_REQUEST_ERR: Raised if this node is of a type that
does not allow children of the type of the newChild
node, or if the node to insert is one of this node's ancestors or this node
itself, or if this node if of type Document and the DOM
application attempts to insert a second DocumentType or Element node.

WRONG_DOCUMENT_ERR: Raised if newChild was created
from a different document than the one that created this node.

NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly or
if the parent of the node being inserted is readonly.

NOT_FOUND_ERR: Raised if refChild is not a child of
this node.

NOT_SUPPORTED_ERR: if this node if of type Document, this exception
might be raised if the DOM implementation doesn't support the
insertion of a DocumentType or Element node.

Tests whether two nodes are equal.
This method tests for equality of nodes, not sameness (i.e.,
whether the two nodes are references to the same object) which can
be tested with Node.isSameNode. All
nodes that are the same will also be equal, though the reverse may
not be true.
Two nodes are equal if and only if the following conditions are
satisfied:

The two nodes are of the same type.

The following string attributes are equal:
nodeName, localName,
namespaceURI, prefix,
nodeValue. This is: they are both null,
or they have the same length and are character for character
identical.

The attributesNamedNodeMaps are equal.
This is: they are both null, or they have the same
length and for each node that exists in one map there is a node
that exists in the other map and is equal, although not necessarily
at the same index.

The childNodesNodeLists are equal. This
is: they are both null, or they have the same length
and contain equal nodes at the same index. Note that normalization
can affect equality; to avoid this, nodes should be normalized
before being compared.

For two DocumentType nodes to be
equal, the following conditions must also be satisfied:

The following string attributes are equal:
publicId, systemId,
internalSubset.

On the other hand, the following do not affect equality: the
ownerDocument, baseURI, and
parentNode attributes, the specified and
attribute for Attr nodes, the
schemaTypeInfo attribute for Attr and Element nodes, the
isWhitespaceInElementContent attribute for Text nodes, as well as
any user data or event listeners registered on the nodes.

Note: As a general rule, anything not mentioned in the
description above is not significant in consideration of equality
checking. Note that future versions of this specification may take
into account more attributes and implementations conform to this
specification are expected to be updated accordingly.

Returns whether this node is the same node as
the given one.
This method provides a way to determine whether two
Node references returned by the implementation
reference the same object. When two Node references
are references to the same object, even if through a proxy, the
references may be used completely interchangeably, such that all
attributes have the same values and calling the same DOM method on
either reference always has exactly the same effect.

This is the version number of the feature to test. In Level 2,
version 1, this is the string "2.0". If the version is
null or empty string, supporting any version of the
feature will cause the method to return true.

Return Value

boolean

Returns true if the specified feature is supported
on this node, false otherwise.

Look up the prefix associated to the given
namespace URI, starting from this node. The default namespace
declarations are ignored by this method.
See Namespace
Prefix Lookup for details on the algorithm used by this method.

Puts all Text nodes in the full
depth of the sub-tree underneath this Node, including
attribute nodes, into a "normal" form where only structure (e.g.,
elements, comments, processing instructions, CDATA sections, and
entity references) separates Text nodes, i.e., there
are neither adjacent Text nodes nor empty Text
nodes. This can be used to ensure that the DOM view of a document
is the same as if it were saved and re-loaded, and is useful when
operations (such as XPointer [XPointer] lookups) that depend on a
particular document tree structure are to be used.

Note: In cases where the document contains CDATASections, the
normalize operation alone may not be sufficient, since XPointers do
not differentiate between Text nodes and CDATASection nodes.

Replaces the child node oldChild
with newChild in the list of children, and returns the
oldChild node.
If newChild is a DocumentFragment object,
oldChild is replaced by all of the DocumentFragment
children, which are inserted in the same order. If the
newChild is already in the tree, it is first removed.

Objects implementing the NamedNodeMap interface are
used to represent collections of nodes that can be accessed by
name. Note that NamedNodeMap does not inherit from NodeList;
NamedNodeMaps are not maintained in any particular
order. Objects contained in an object implementing
NamedNodeMap may also be accessed by an ordinal index,
but this is simply to allow convenient enumeration of the contents
of a NamedNodeMap, and does not imply that the DOM
specifies an order to these Nodes.

Removes a node specified by name. When this map
contains the attributes attached to an element, if the removed
attribute is known to have a default value, an attribute
immediately appears containing the default value as well as the
corresponding namespace URI, local name, and prefix when
applicable.

Removes a node specified by local name and
namespace URI. A removed attribute may be known to have a default
value when this map contains the attributes attached to an element,
as returned by the attributes attribute of the Node interface. If so,
an attribute immediately appears containing the default value as
well as the corresponding namespace URI, local name, and prefix
when applicable.
Per [XML Namespaces], applications must
use the value null as the namespaceURI parameter for methods if
they wish to have no namespace.

Adds a node using its nodeName
attribute. If a node with that name is already present in this map,
it is replaced by the new one. Replacing a node by itself has no
effect.
As the nodeName attribute is used to derive the name
which the node must be stored under, multiple nodes of certain
types (those that have a "special" string value) cannot be stored
as the names would clash. This is seen as preferable to allowing
nodes to be aliased.

WRONG_DOCUMENT_ERR: Raised if arg was created from
a different document than the one that created this map.

NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly.

INUSE_ATTRIBUTE_ERR: Raised if arg is an Attr that is already an
attribute of another Element object. The DOM
user must explicitly clone Attr nodes to re-use them
in other elements.

HIERARCHY_REQUEST_ERR: Raised if an attempt is made to add a
node doesn't belong in this NamedNodeMap. Examples would include
trying to insert something other than an Attr node into an
Element's map of attributes, or a non-Entity node into the
DocumentType's map of Entities.

Adds a node using its namespaceURI
and localName. If a node with that namespace URI and
that local name is already present in this map, it is replaced by
the new one. Replacing a node by itself has no effect.
Per [XML Namespaces], applications must
use the value null as the namespaceURI parameter for methods if
they wish to have no namespace.

WRONG_DOCUMENT_ERR: Raised if arg was created from
a different document than the one that created this map.

NO_MODIFICATION_ALLOWED_ERR: Raised if this map is readonly.

INUSE_ATTRIBUTE_ERR: Raised if arg is an Attr that is already an
attribute of another Element object. The DOM
user must explicitly clone Attr nodes to re-use them
in other elements.

HIERARCHY_REQUEST_ERR: Raised if an attempt is made to add a
node doesn't belong in this NamedNodeMap. Examples would include
trying to insert something other than an Attr node into an
Element's map of attributes, or a non-Entity node into the
DocumentType's map of Entities.

NOT_SUPPORTED_ERR: May be raised if the implementation does not
support the feature "XML" and the language exposed through the
Document does not support XML Namespaces (such as [HTML
4.01]).

The CharacterData interface extends Node with a set
of attributes and methods for accessing character data in the DOM.
For clarity this set is defined here rather than on each object
that uses these attributes and methods. No DOM objects correspond
directly to CharacterData, though Text and others do
inherit the interface from it. All offsets in this
interface start from 0.

As explained in the DOMString interface, text
strings in the DOM are represented in UTF-16, i.e. as a sequence of
16-bit units. In the following, the term 16-bit units is used
whenever necessary to indicate that indexing on CharacterData is
done in 16-bit units.

The character data of the node that implements this interface.
The DOM implementation may not put arbitrary limits on the amount
of data that may be stored in a CharacterData node.
However, implementation limits may mean that the entirety of a
node's data may not fit into a single DOMString. In such cases,
the user may call substringData to retrieve the data
in appropriately sized pieces.When the CharacterData is
a Text, or a CDATASection, this
attribute contains the property [character code] defined in [XML
Information set]. When the CharacterData
is a Comment,
this attribute contains the property [content] defined by the
Comment Information Item in [XML Information set].

Replace the characters starting at the
specified 16-bit
unit offset with the specified string.

Parameters

offset of type
unsigned long

The offset from which to start replacing.

count of type
unsigned long

The number of 16-bit units to replace. If the sum of
offset and count exceeds
length, then all 16-bit units to the end of the data
are replaced; (i.e., the effect is the same as a
remove method call with the same range, followed by an
append method invocation).

The Attr interface represents an attribute in an Element object.
Typically the allowable values for the attribute are defined in a
document type definition.

Attr objects inherit the Node interface, but
since they are not actually child nodes of the element they
describe, the DOM does not consider them part of the document tree.
Thus, the Node attributes
parentNode, previousSibling, and
nextSibling have a null value for
Attr objects. The DOM takes the view that attributes
are properties of elements rather than having a separate identity
from the elements they are associated with; this should make it
more efficient to implement such features as default attributes
associated with all elements of a given type. Furthermore,
Attr nodes may not be immediate children of a DocumentFragment. However,
they can be associated with Element nodes contained
within a DocumentFragment. In
short, users and implementors of the DOM need to be aware that
Attr nodes have some things in common with other
objects inheriting the Node interface, but they
also are quite distinct.

The attribute's effective value is determined as follows: if
this attribute has been explicitly assigned any value, that value
is the attribute's effective value; otherwise, if there is a
declaration for this attribute, and that declaration includes a
default value, then that default value is the attribute's effective
value; otherwise, the attribute does not exist on this element in
the structure model until it has been explicitly added. Note that
the nodeValue attribute on the Attr
instance can also be used to retrieve the string version of the
attribute's value(s).

In XML, where the value of an attribute can contain entity
references, the child nodes of the Attr node may be
either Text or
EntityReference
nodes (when these are in use; see the description of EntityReference for
discussion). Because the DOM Core is not aware of attribute types,
it treats all attribute values as simple strings, even if the DTD
or schema declares them as having tokenized types.

The DOM implementation does not perform any kind of
normalization. While it is expected that the value and
nodeValue attributes of an Attr node
would initially return a normalized value depending on the schema
in used, this may not be the case after mutation. This is true,
independently of whether the mutation is performed by setting the
string value directly or by changing the Attr child
nodes. In particular, this is true when character entity references
are involved, given that they are not represented in the DOM and
they impact attribute value normalization.

True if this attribute was explicitly given a
value in the instance document, false otherwise. If
the user changes the value of this attribute node (even if it ends
up having the same value as the default value) then this is set to
true. Removing attributes for which a default value is
defined in the DTD generates a new attribute with the default value
and this set to false. The implementation may handle
attributes with default values from other schemas similarly but
applications should use normalizeDocument() to
guarantee this information is up-to-date.This
attribute is based on the property [specified] defined [XML Information
set].

On retrieval, the value of the attribute is returned as a
string. Character and general entity references are replaced with
their values. See also the method getAttribute on the
Element
interface.
On setting, this creates a Text node with the
unparsed contents of the string. I.e. any characters that an XML
processor would recognize as markup are instead treated as literal
text. See also the method setAttribute on the Element interface.

Note: Some specialized implementations, such as some [SVG 1.0]
implementations, may do normalization automatically, even after
mutation; in such case, the value on retrieval may differ from the
value on setting.

The value may contain
the normalized attribute value and represents in that case the
property [normalized value] defined in [XML Information set].

The Element interface represents an element in an HTML or XML
document. Elements may have attributes associated with them; since
the Element interface inherits from Node, the generic Node
interface attribute attributes may be used to retrieve
the set of all attributes for an element. There are methods on the
Element interface to retrieve either an Attr object by name or an
attribute value by name. In XML, where an attribute value may
contain entity references, an Attr object should be
retrieved to examine the possibly fairly complex sub-tree
representing the attribute value. On the other hand, in HTML, where
all attributes have simple string values, methods to directly
access an attribute value can safely be used as a convenience.

Note: In DOM Level 2, the method normalize
is inherited from the Node interface where it
was moved.

Note:The property [in-scope namespaces] defined
in [XML
Information set] are not accessible from DOM Level 3 Core.
However, [DOM Level 3 XPath] does provide a
way to access the property [in-scope namespaces].

tagName has the value "elementExample".
Note that this is case-preserving in XML, as are all of the
operations of the DOM. The HTML DOM returns the
tagName of an HTML element in the canonical uppercase
form, regardless of the case in the source HTML document.

Returns true when an attribute
with a given local name and namespace URI is specified on this
element or has a default value, false otherwise.
Per [XML Namespaces], applications must
use the value null as the namespaceURI parameter for methods if
they wish to have no namespace.

Removes an attribute by name. If a default
value for the removed attribute is defined in the DTD, a new
attribute immediately appears with the default value as well as the
corresponding namespace URI, local name, and prefix when
applicable. The implementation may handle default values from other
schemas similarly but applications should use normalizeDocument()
to guarantee this information is up-to-date.
If no attribute with this name is found, this method has no
effect.
To remove an attribute by local name and namespace URI, use the
removeAttributeNS method.

Removes an attribute by local name and
namespace URI. If a default value for the removed attribute is
defined in the DTD, a new attribute immediately appears with the
default value as well as the corresponding namespace URI, local
name, and prefix when applicable. The implementation may handle
default values from other schemas similarly but applications should
use normalizeDocument() to guarantee this information is
up-to-date.
If no attribute with this local name and namespace URI is found,
this method has no effect.
Per [XML Namespaces], applications must
use the value null as the namespaceURI parameter for methods if
they wish to have no namespace.

Removes the specified attribute node. If a
default value for the removed Attr node is defined in
the DTD, a new node immediately appears with the default value as
well as the corresponding namespace URI, local name, and prefix
when applicable. The implementation may handle default values from
other schemas similarly but applications should use
normalizeDocument() to guarantee this information is up-to-date.

Adds a new attribute. If an attribute with that
name is already present in the element, its value is changed to be
that of the value parameter. This value is a simple string; it is
not parsed as it is being set. So any markup (such as syntax to be
recognized as an entity reference) is treated as literal text, and
needs to be appropriately escaped by the implementation when it is
written out. In order to assign an attribute value that contains
entity references, the user must create an Attr node plus any Text and EntityReference nodes,
build the appropriate subtree, and use
setAttributeNode to assign it as the value of an
attribute.
To set an attribute with a qualified name and namespace URI, use
the setAttributeNS method.

Adds a new attribute. If an attribute with the
same local name and namespace URI is already present on the
element, its prefix is changed to be the prefix part of the
qualifiedName, and its value is changed to be the
value parameter. This value is a simple string; it is
not parsed as it is being set. So any markup (such as syntax to be
recognized as an entity reference) is treated as literal text, and
needs to be appropriately escaped by the implementation when it is
written out. In order to assign an attribute value that contains
entity references, the user must create an Attr node plus any Text and EntityReference nodes,
build the appropriate subtree, and use
setAttributeNodeNS or setAttributeNode to
assign it as the value of an attribute.
Per [XML Namespaces], applications must
use the value null as the namespaceURI parameter for methods if
they wish to have no namespace.

INVALID_CHARACTER_ERR: Raised if the specified qualified name
contains an illegal character.

NO_MODIFICATION_ALLOWED_ERR: Raised if this node is
readonly.

NAMESPACE_ERR: Raised if the qualifiedName is
malformed per the Namespaces in XML specification, if the
qualifiedName has a prefix and the
namespaceURI is null, if the
qualifiedName has a prefix that is "xml" and the
namespaceURI is different from "http://www.w3.org/XML/1998/namespace",
if the qualifiedName or its prefix is "xmlns" and the
namespaceURI is different from "http://www.w3.org/2000/xmlns/",
or if the namespaceURI is "http://www.w3.org/2000/xmlns/"
and neither the qualifiedName nor its prefix is
"xmlns".

NOT_SUPPORTED_ERR: May be raised if the implementation does not
support the feature "XML" and the language exposed through the
Document does not support XML Namespaces (such as [HTML
4.01]).

Adds a new attribute node. If an attribute with
that name (nodeName) is already present in the
element, it is replaced by the new one. Replacing an attribute node
by itself has no effect.
To add a new attribute node with a qualified name and namespace
URI, use the setAttributeNodeNS method.

Adds a new attribute. If an attribute with that
local name and that namespace URI is already present in the
element, it is replaced by the new one. Replacing an attribute node
by itself has no effect.
Per [XML Namespaces], applications must
use the value null as the namespaceURI parameter for methods if
they wish to have no namespace.

Declares the attribute specified by name to be
of type ID. If the value of the specified attribute is unique then
this element node can later be retrieved using
getElementById on Document. Note, however,
that this simply affects this node and does not change any grammar
that may be in use. Consequently, it may be reset according to the
grammar when the document is normalized.
To specify an attribute by local name and namespace URI, use the
setIdAttributeNS method.

removeAttribute is a no-op if the attribute does not exist.
Does it matter?Resolution: removeAttribute is fine as a no-op because the
application gets the right result. This isn't true here. So keep
the exception. (Telcon 2002 June 12)

Declares the attribute specified by local name
and namespace URI to be of type ID. If the value of the specified
attribute is unique then this element node can later be retrieved
using getElementById on Document. Note, however,
that this simply affects this node and does not change any grammar
that may be in use. Consequently, it may be reset according to the
grammar when the document is normalized.

removeAttributeNS is a no-op if the attribute does not exist.
Does it matter?Resolution: removeAttributeNS is fine as a no-op because the
application gets the right result. This isn't true here. So keep
the exception. (Telcon 2002 June 12)

Declares the attribute specified by node to be
of type ID. If the value of the specified attribute is unique then
this element node can later be retrieved using
getElementById on Document. Note, however,
that this simply affects this node and does not change any grammar
that may be in use. Consequently, it may be reset according to the
grammar when the document is normalized.

The Text interface inherits from CharacterData and
represents the textual content (termed character
data in XML) of an Element or Attr. If there is no
markup inside an element's content, the text is contained in a
single object implementing the Text interface that is
the only child of the element. If there is markup, it is parsed
into the information
items (elements, comments, etc.) and Text
nodes that form the list of children of the element.

When a document is first made available via the DOM, there is
only one Text node for each block of text. Users may
create adjacent Text nodes that represent the contents
of a given element without any intervening markup, but should be
aware that there is no way to represent the separations between
these nodes in XML or HTML, so they will not (in general) persist
between DOM editing sessions. The normalize method on
Node merges any
such adjacent Text objects into a single node for each
block of text.

Substitutes the specified text for the text of
the current node and all logically-adjacent
text nodes.
This method returns the node in the hierarchy which received the
replacement text, which is null if the text was empty or is the
current node if the current node is not read-only or otherwise is a
new node of the same type as the current node inserted at the site
of the replacement. All logically-adjacent
text nodes are removed including the current node unless
it was the recipient of the replacement text.
Where the nodes to be removed are read-only descendants of an EntityReference, the
EntityReference must be
removed instead of the read-only nodes. If any EntityReference to be
removed has descendants that are not EntityReference,
Text, or CDATASection nodes, the
replaceWholeText method must fail before performing
any modification of the document, raising a DOMException with the code
NO_MODIFICATION_ALLOWED_ERR.

Breaks this node into two nodes at the
specified offset, keeping both in the tree as siblings. After being
split, this node will contain all the content up to the
offset point. A new node of the same type, which
contains all the content at and after the offset
point, is returned. If the original node had a parent node, the new
node is inserted as the next sibling of the original
node. When the offset is equal to the length of this
node, the new node has no data.

This interface inherits from CharacterData and
represents the content of a comment, i.e., all the characters
between the starting '<!--' and ending
'-->'. Note that this is the definition of a
comment in XML, and, in practice, HTML, although some HTML tools
may implement the full SGML comment structure.

The TypeInfo interface represent a type referenced
from Element or
Attr nodes,
specified in the schemas associated with the document. The type is
a pair of a namespace
URI and name properties, and depends on the document's
schema.

should you be able to return null on
typeName? for anonymous type? for undeclared
elements/attributes? Can schemaType be null?Resolution: schemaTypeInfo can never be null [f2f October
2002].

If the document's schema is an XML DTD [XML 1.0], the
values are computed as follows:

If this type is referenced from an Attr node,
typeNamespace is null and typeName represents the
[attribute type] property in the [XML Information set]. If there is no
declaration for the attribute, typeName is
null.

Unlike for XML Schema, the name contain the declared type, and
does not relate to "validity".Resolution: Resolved using Elena's proposal.

If this type is referenced from an Element node, the
typeNamespace and typeName are
null.

If the document's schema is an XML Schema [XML Schema
Part 1], the values are computed as follows using the
post-schema-validation infoset contributions (also called PSVI
contributions):

If the [validity] property exists AND is "invalid" or
"notKnown": the {target namespace} and {name} properties
of the declared type if available, otherwise null.

Note: At the time of writing, the XML Schema
specification does not require exposing the declared type. Thus,
DOM implementations might choose not to provide type information if
validity is not valid.

If the [validity] property exists and is "valid":

If [member type definition] exists, then expose the {target
namespace} and {name} properties of the [member type definition]
property;

If the [member type definition namespace] and the [member type
definition name] exist, then expose these properties.

If the [type definition] property exists, then expose the
{target namespace} and {name} properties of the [type definition]
property;

If the [type definition namespace] and the [type definition
name] exist, then expose these properties.

Note: At the time of writing, the XML Schema
specification does not define how to expose anonymous types. If
future specifications define how to expose anonymous types, DOM
implementations can expose anonymous types via
typeName and typeNamespace
parameters.

Note: Other schema languages are outside the scope of the
W3C and therefore should define how to represent their type systems
using TypeInfo.

The namespace of the type declared for the associated element
or attribute or null if the element does not have
declaration or if no namespace information is available.
Implementations may also use null to represent XML
Schema anonymous types.

When associating an object to a key on a node using
setUserData the application can provide a handler that
gets called when the node the object is associated to is being
cloned, imported, or renamed. This can be used by the application
to implement various behaviors regarding the data it associates to
the DOM nodes. This interface defines that handler.

A DOMString
indicating which related data is expected in
relatedData. Users should refer to the specification
of the error in order to find its DOMString type and
relatedData definitions if any.

Note: As an example, [DOM Level 3 Load and Save] does not
keep the [baseURI] property defined on a Processing Instruction
information item. Therefore, the DOMBuilder generates
a SEVERITY_WARNING with type"infoset-baseURI" and the lost [baseURI] property
represented as a DOMString in the
relatedData attribute.

DOMErrorHandler is a callback interface that the
DOM implementation can call when reporting errors that happens
while processing XML data, or when doing some other processing
(e.g. validating a document).

The application that is using the DOM implementation is expected
to implement this interface.

The error object that describes the error, this object may be
reused by the DOM implementation across multiple calls to the
handleEvent method.

Return Value

boolean

If the handleError method returns true the DOM
implementation should continue as if the error didn't happen when
possible, if the method returns false then the DOM
implementation should stop the current processing when
possible.

The byte or character offset into the input source this locator
is pointing to. If the input source is a file or a byte stream then
this is the byte offset into that stream, but if the input source
is a character media then the offset is the character offset. The
value is -1 if there is no offset available.

The DOMConfiguration interface represents the
configuration of a document and maintains a table of recognized
parameters. Using the configuration, it is possible to change Document.normalizeDocument
behavior, such as replacing the CDATASection nodes with
Text nodes or
specifying the type of the schema that must be used when the
validation of the Document is requested.
DOMConfiguration objects are also used in [DOM Level 3 Load
and Save] in the DOMBuilder and
DOMWriter interfaces.

The DOMConfiguration distinguish two types of
parameters: boolean (boolean parameters) and DOMUserData (parameters).
The names used by the DOMConfiguration object are
defined throughout the DOM Level 3 specifications. Names are
case-insensitives. To avoid possible conflicts, as a convention,
names referring to boolean parameters and parameters defined
outside the DOM specification should be made unique. Names are
recommended to follow the XML name production rule
but it is not enforced by the DOM implementation. DOM Level 3 Core
Implementations are required to recognize all boolean parameters
and parameters defined in this specification. Each boolean
parameter state or parameter value may then be supported or not by
the implementation. Refer to their definition to know if a state or
a value must be supported or not.

Note: Parameters are similar to features and properties
used in SAX2 [SAX].

Are boolean parameters and parameters within the same scope for
uniqueness? Which exception should be raised by
setBooleanParameter("error-handler", true)?

The following list of parameters defined in the DOM:

"error-handler"

[required]
A DOMErrorHandler
object. If an error is encountered in the document, the
implementation will call back the DOMErrorHandler
registered using this parameter.
When called, DOMError.relatedData
will contain the closest node to where the error occured. If the
implementation is unable to determine the node where the error
occurs, DOMError.relatedData
will contain the Document node. Mutations to
the document from within an error handler will result in
implementation dependent behaviour.

[optional]
A DOMString object
containing an absolute URI and representing the type of the schema
language used to validate a document against. Note that no lexical
checking is done on the absolute URI.
If this parameter is not set, a default value may be provided by
the implementation, based on the schema languages supported and on
the schema language used at load time.

Note: For XML Schema [XML Schema Part 1], applications
must use the value "http://www.w3.org/2001/XMLSchema".
For XML DTD [XML 1.0], applications must use the value
"http://www.w3.org/TR/REC-xml". Other schema languages
are outside the scope of the W3C and therefore should recommend an
absolute URI in order to use this method.

"schema-location"

[optional]
A DOMString object
containing a list of URIs, separated by white spaces (characters
matching the nonterminal
production S defined in section 2.3 [XML 1.0]), that
represents the schemas against which validation should occur. The
types of schemas referenced in this list must match the type
specified with schema-type, otherwise the behaviour of
an implementation is undefined. If the schema type is XML Schema
[XML
Schema Part 1], only one of the XML Schemas in the list can be
with no namespace.
If validation occurs against a namespace aware schema, i.e. XML
Schema, and the targetNamespace of a schema (specified using this
property) matches the targetNamespace of a schema occurring in the
instance document, i.e in schemaLocation attribute, the schema
specified by the user using this property will be used (i.e., in
XML Schema the schemaLocation attribute in the
instance document or on the import element will be
effectively ignored).

Note: It is illegal to set the schema-location parameter
if the schema-type parameter value is not set. It is strongly
recommended that DOMInputSource.baseURI will be set,
so that an implementation can successfully resolve any external
entities referenced.

The following list of boolean parameters (features) defined in
the DOM:

"canonical-form"

true

[optional]
Canonicalize the document according to the rules specified in [Canonical
XML]. Note that this is limited to what can be represented in
the DOM. In particular, there is no way to specify the order of the
attributes in the DOM.

[required] (default)
Use whatever information available to the implementation (i.e. XML
schema, DTD, the specified flag on Attr nodes, and so on) to
decide what attributes and content should be discarded or not. Note
that the specified flag on Attr nodes in itself is
not always reliable, it is only reliable when it is set to
false since the only case where it can be set to
false is if the attribute was created by the
implementation. The default content won't be removed if an
implementation does not have any information available.

How does that interact with expand-entity-references? ALH
suggests consolidating the two to a single feature called
"entity-references" that is used both for load and save.Resolution: Consolidate both features into a single feature
called 'entities'. (Telcon 27 Jan 2002).

false

[required] (default)
Remove all EntityReference and Entity nodes from the
document, putting the entity expansions directly in their place. Text nodes are into
"normal" form. Only EntityReference nodes to
non-defined entities are kept in the document.

"infoset"

true

[required]
Only keep in the document the information defined in the XML
Information Set [XML Information set].
This forces the following features to false:
namespace-declarations,
validate-if-schema, entities,
datatype-normalization,
cdata-sections.
This forces the following features to true:
whitespace-in-element-content, comments,
namespaces.
Other features are not changed unless explicity specified in the
description of the features.
Note that querying this feature with getFeature
returns true only if the individual features specified
above are appropriately set.

[required]
Signal an error if a CDATASection contains an
unrepresentable character.

"validate"

true

[optional]
Require the validation against a schema (i.e. XML schema, DTD, any
other type or representation of schema) of the document as it is
being normalized as defined by [XML 1.0]. If validation errors are found,
or no schema was found, the error handler is notified. Note also
that normalized values will not be exposed to the schema in used
unless the feature datatype-normalization is
true.

Note:validate-if-schema and
validate are mutually exclusive, setting one of them
to true will set the other one to
false.

false

[required] (default)
Only XML 1.0 non-validating processing must be done. Note that
validation might still happen if validate-if-schema is
true.

"validate-if-schema"

true

[optional]
Enable validation only if a declaration for the document element
can be found (independently of where it is found, i.e. XML schema,
DTD, or any other type or representation of schema). If validation
errors are found, the error handler is notified. Note also that
normalized values will not be exposed to the schema in used unless
the feature datatype-normalization is
true.

Note:validate-if-schema and
validate are mutually exclusive, setting one of them
to true will set the other one to
false.

false

[required] (default)
No validation should be performed if the document has a schema.
Note that validation must still happen if validate is
true.

[optional]
Discard white space in element content while normalizing. The
implementation is expected to use the
isWhitespaceInElementContent flag on Text nodes to determine
if a text node should be written out or not.

The resolutions of entities is done using
Document.baseURI. However, when the features "LS-Load"
or "LS-Save" defined in [DOM Level 3 Load and Save] are
supported by the DOM implementation, the parameter
"entity-resolver" can also be used on
DOMConfiguration objects attached to Document nodes. If this
parameter is set, Document.normalizeDocument
will invoke the entity resolver instead of using
Document.baseURI.

true if the parameter could be successfully set to
the specified value, or false if the parameter is not
recognized or the requested value is not supported. This does not
change the current value of the parameter itself.

The new value or null if the user wishes to unset
the parameter. While the type of the value parameter is defined as
DOMUserData, the object
type must match the type defined by the definition of the
parameter. For example, if the parameter is
"error-handler", the value must be of type DOMErrorHandler.

NOT_SUPPORTED_ERR: Raised when the parameter name is recognized
but the requested value cannot be set.

NOT_FOUND_ERR: Raised when the parameter name is not
recognized.

No Return Value

1.3. Extended Interfaces

The interfaces defined here form part of the DOM Core
specification, but objects that expose these interfaces will never
be encountered in a DOM implementation that deals only with
HTML.

The interfaces found within this section are not mandatory. A
DOM application may use the hasFeature(feature,
version) method of the DOMImplementation
interface with parameter values "XML" and "3.0" (respectively) to
determine whether or not this module is supported by the
implementation. In order to fully support this module, an
implementation must also support the "Core" feature defined in Fundamental Interfaces. Please
refer to additional information about Conformance in this
specification. The DOM Level 3 XML module is backward compatible
with the DOM Level 2 XML [DOM Level 2 Core] and DOM Level 1
XML [DOM Level 1] modules, i.e. a DOM
Level 3 XML implementation who returns true for "XML"
with the version number "3.0" must also
return true for this feature when the
version number is "2.0",
"1.0", "" or, null.

CDATA sections are used to escape blocks of text containing
characters that would otherwise be regarded as markup. The only
delimiter that is recognized in a CDATA section is the "]]>"
string that ends the CDATA section. CDATA sections cannot be
nested. Their primary purpose is for including material such as XML
fragments, without needing to escape all the delimiters.

The DOMString
attribute of the Text node holds the text
that is contained by the CDATA section. Note that this may
contain characters that need to be escaped outside of CDATA
sections and that, depending on the character encoding ("charset")
chosen for serialization, it may be impossible to write out some
characters as part of a CDATA section.

The CDATASection interface inherits from the CharacterData
interface through the Text interface. Adjacent
CDATASection nodes are not merged by use of the
normalize method of the Node interface.

Note: Because no markup is recognized within a
CDATASection, character numeric references cannot be
used as an escape mechanism when serializing. Therefore, action
needs to be taken when serializing a CDATASection with
a character encoding where some of the contained characters cannot
be represented. Failure to do so would not produce well-formed
XML.
One potential solution in the serialization process is to end the
CDATA section before the character, output the character using a
character reference or entity reference, and open a new CDATA
section for any further characters in the text node. Note, however,
that some code conversion libraries at the time of writing do not
return an error or exception when a character is missing from the
encoding, making the task of ensuring that data is not corrupted on
serialization more difficult.

Each Document
has a doctype attribute whose value is either
null or a DocumentType object. The
DocumentType interface in the DOM Core provides an
interface to the list of entities that are defined for the
document, and little else because the effect of namespaces and the
various XML schema efforts on DTD representation are not clearly
understood as of this writing.

the interface provides access to foo and the first
declaration of bar but not the second declaration of
bar or baz. Every node in this map also
implements the Entity interface.
The DOM Level 2 does not support editing entities, therefore
entities cannot be altered in any way.

The internal subset as a string, or null if there
is none. This is does not contain the delimiting square brackets.

Note: The actual content returned depends on how much
information is available to the implementation. This may vary
depending on various parameters, including the XML processor used
to build the document.

A NamedNodeMap containing
the notations declared in the DTD. Duplicates are discarded. Every
node in this map also implements the Notation interface.
The DOM Level 2 does not support editing notations, therefore
notations cannot be altered in any way.This
attribute represents the property [notations] defined by the
Document Information Item in [XML Information set].

The system identifier of the external subset. This may be an
absolute URI or not.This attribute represents
the property [system identifier] defined by the Document Type
Declaration Information Item in [XML Information set].

This interface represents a notation declared in the DTD. A
notation either declares, by name, the format of an unparsed entity
(see section
4.7 of the XML 1.0 specification [XML 1.0]), or is
used for formal declaration of processing instruction targets (see
section
2.6 of the XML 1.0 specification [XML 1.0]). The
nodeName attribute inherited from Node is set to the
declared name of the notation.

The DOM Core does not support editing Notation
nodes; they are therefore readonly.

The public identifier of this notation. If the public
identifier was not specified, this is null.This attribute represents
the property [public identifier] defined by the Notation
Information Item in [XML Information set].

The system identifier of this notation. If the system
identifier was not specified, this is null. This may
be an absolute URI or not.This attribute represents
the property [system identifier] defined by the Notation
Information Item in [XML Information set].

This interface represents a known entity, either parsed or
unparsed, in an XML document. Note that this models the entity
itself not the entity declaration.

The nodeName attribute that is inherited from Node contains the
name of the entity.

An XML processor may choose to completely expand entities before
the structure model is passed to the DOM; in this case there will
be no EntityReference nodes in
the document tree.

XML does not mandate that a non-validating XML processor read
and process entity declarations made in the external subset or
declared in external parameter entities. This means that parsed
entities declared in the external subset need not be expanded by
some classes of applications, and that the replacement text of the
entity may not be available. When the
replacement text is available, the corresponding
Entity node's child list represents the structure of
that replacement value. Otherwise, the child list is empty.

The DOM Level 2 does not support editing Entity
nodes; if a user wants to make changes to the contents of an
Entity, every related EntityReference node has
to be replaced in the structure model by a clone of the
Entity's contents, and then the desired changes must
be made to each of those clones instead. Entity nodes
and all their descendants are readonly.

An Entity node does not have any parent.

Note: If the entity contains an unbound namespace prefix,
the namespaceURI of the corresponding node in the
Entity node subtree is null. The same is
true for EntityReference nodes that
refer to this entity, when they are created using the
createEntityReference method of the Document interface. The DOM
Level 2 does not support any mechanism to resolve namespace
prefixes.

Note: The properties [notation name] and [notation]
defined in [XML Information set] are not
accessible from DOM Level 3 Core.

The public identifier associated with the entity if specified,
and null otherwise.This attribute represents the
property [public identifier] defined by the Unparsed Entity
Information Item in [XML Information set].

The system identifier associated with the entity if specified,
and null otherwise. This may be an absolute URI or
not.This attribute represents the
property [system identifier] defined by the Unparsed Entity
Information Item in [XML Information set].

EntityReference nodes may be used to represent an
entity reference in the tree. Note that character references and
references to predefined entities are considered to be expanded by
the HTML or XML processor so that characters are represented by
their Unicode equivalent rather than by an entity reference.
Moreover, the XML processor may completely expand references to
entities while building the Document, instead of
providing EntityReference nodes. If it does provide
such nodes, then for an EntityReference node that
represents a reference to a known entity an Entity exists, and the
subtree of the EntityReference node is a copy of the
Entity node subtree.
However, the latter may not be true when an entity contains an
unbound namespace
prefix. In such a case, because the namespace prefix
resolution depends on where the entity reference is, the descendants of the
EntityReference node may be bound to different namespace URIs.
When an EntityReference node represents a reference to
an unknown entity, its content is empty.

Note: The properties [system identifier] and [public
identifier] defined by the Unexpanded Entity Reference Information
Item in [XML Information set] are accessible
through the Entity
interface. The property [all declarations processed] is not
accessible through the DOM API.

Note:EntityReference nodes may cause
element content and attribute value normalization problems when,
such as in XML 1.0 and XML Schema, the normalization is be
performed after entity reference are expanded.

The content of this processing instruction. This is from the
first non white space character after the target to the character
immediately preceding the ?>.This
attribute represents the property [content] defined by the
Processing Instruction Information Item in [XML Information
set].

The target of this processing instruction. XML defines this as
being the first token
following the markup that begins the processing instruction.This attribute
represents the property [target] defined in [XML Information
set].